New Enzyme Can Neutralize Chemical Weapons

Texas A&M University chemist, Dr. Frank Raushel, is contributing to America’s war against terror by developing an enzyme that might neutralize a deadly chemical agent, the organophosphates. The organophosphates started their journey as insecticides in the 1930s but soon made their way into the dangerous alleys of chemical warfare during World War II as the basis for deadly nerve agents such as Sarin, Tabun, and Soman.

Dr. Frank Raushel
(Credit: Texas A&M University)

Despite being outlawed by several international treaties, some countries have used chemical agents during times of war. In 1988, the Iraqi Kurdish village of Halabja was exposed to multiple chemical agents, killing about 5,000 of the town’s 50,000 residents. After the incident, traces of mustard gas and several nerve agents were discovered. The mass murder was perpetrated by orders of Saddam Hussein as retribution for the Kurdish uprising and in order to test his chemical weapons.

Organophosphates fall under the category of neurotoxins, which attack the nervous system by blocking the function of an important enzyme, which carries nerve signals throughout the body. When vital organs, such as the lungs, do not receive the appropriate nerve signals, control is lost over respiratory muscles, which usually results in death by asphyxiation. Today, some classes of organophosphates are used as insecticides while others have been categorized as chemical weapons.

The structure of Phosphotriesterase
(Credit: Dave Flanagan/University of
Massachusetts Amherst)

Dr. Raushel and his team have discovered a bacterial enzyme, phosphotriesterase, which can recognize and destroy the toxicity of a broad spectrum of organophosphate nerve agents. What Raushel aims to do now is to design and characterize bacterial phosphotriesterases that are better at detecting, destroying and detoxifying those organophosphates that pose the most serious threats to human health.